The most popular social networking sites sure have changed over the years, and you can expect them to continue to change as times goes on. Old social media trends will die, and new ones will appear.

Before Facebook and Twitter dominated the web, we were a lot more familiar with sites like MySpace and LiveJournal. Although there are some people who still use older social networks like MySpace and LiveJournal, most people can probably admit to moving on to newer, cooler social sites -- especially with the recent shift toward mobile-based social media consumption.

Here is a short roundup of a few of the trendiest social networks people are using both on the web and on mobile right now.

1. Facebook

Most of us already know that Facebook is the top social network on the web. It's a thriving beast of a social networking site on the web over a billions users. Despite holding the spot on the entire Internet for years now, it has to lead you to wonder just how long and what it might take for Facebook to eventually be brought down to a lower spot on the popular social site list. Time will only tell.

2. Twitter

Like Facebook, Twitter has also changed dramatically over the years, becoming a top source for real-time news sharing. For a microblogging site with a 140-character text limit, Twitter sure has made its mark online. Its an ideal platform for mobile users, and Twitter Card integration make it easy to share all sorts of multimedia content in tweets.

3. Google+

Making its debut in the early summer of 2011, Google+ became the fastest growing social network the web has ever seen. After failing a couple times already with Google Buzz and Google Wave, the search giant finally succeeded at creating something that people are actually excited about using -- especially alongside all the other popular Google apps and services.

4. YouTube

Where does everyone go to watch or share video content online? It's obviously YouTube. After Google, YouTube is the second largest search engine. Although owned by Google and now tied right into our Google+ accounts, YouTube can still be recognized as a separate social network all on its own as one that revolves entirely around content like video production, vlogging, movie-making and music sharing.

5. LinkedIn

Anyone who needs to make professional connections should be on LinkedIn. Known as the social network for your career, LinkedIn is right up there with Facebook, Twitter and Google+. Individuals can promote themselves and their businesses, outline their education and work experience, make connections with other professionals, interact in group discussions, post job ads or apply for jobs.

6. Instagram

Instagram has grown to be one of the most popular social networks for photo sharing that the mobile web has ever seen. It's the ultimate social network for sharing real-time photos and short videos while on the go. The app started by being exclusively limited to the iOS platform, but has since expanded to Android and, Windows Phone also the web. Instagram was bought for a hefty $1 billion in 2012.

7. Pinterest

Pinterest is quickly becoming a major player in social networking, and proves just how important visual content has become on he web. As the fastest standalone site ever to reach 10 million monthly unique visits, Pinterest's beautiful and intuitive pinboard-style platform on the web and on mobile is one of the most incredible resources for collecting the best images and categorizing them on your own boards.

8. Tumblr

Tumblr is an extremely popular social blogging platform heavily used by teens and younger users. Like Pinterest, it's popular for sharing visual content. You can customize your blog theme, post all different tpes of content formats, follow other users and be followed back. Reblogging and “liking” is a popular way to interact. If you post great content, you might be surprised to see how many followers you can attract.

9. Vine

Vine is mobile video-sharing app owned by Twitter. One of the most convenient things about Vine is that its videos can be directly embedded inline on Twitter when shared through a tweet -- or even embedded on a website. Videos play on autoloop and are limited to a maximum of six seconds, but that doesn't stop it from being such a powerful social network. Many prefer it over Instagram video.

10. Snapchat

Snapchat is a social network based on instant messaging, and it's totally mobile-based. It's one of the fastest growing apps out there, building its popularity on the idea of self-destructing "snaps" -- photos or short videos you take to chat with friends before they automatically delete after viewing. It's a massive social app for kids. If you're unfamiliar, check out this step-by-step tutorial on how to use Snapchat.

11. Reddit

Reddit resembles the traditional message board style we all know and love. It has a very strong and smart community, and Reddit AMAs are one of the best ways to take advantage of this platform. Reddit works by displaying submitted links to content that get voted up or down by users. Links that receive the most upvotes will get pushed to the first page of their subreddits for being the best content voted by the users.

12. Flickr

Flickr is Yahoo's popular photo-sharing network, which exited long before other popular image-based social sites like Pinterest and Instagram excited. It's still one of the best places to upload photos, create albums and show off your photography skills to your friends. Yahoo has also worked hard at regularly updating its mobile apps with lots of great features and functions so it's easy to use from your phone.

13. Swarm (by Foursquare)Foursquare has broken up its location-based app into two parts. While its main Foursquare app is now meant to be used as a location discovery tool, its Swarm app is all about being social. You use it to see where your friends are, let them know where you are by checking in, and then you can use it to chat and plan to meet up at a specific location sometime later. 14. TVtag (Formerly GetGlue)

GetGlue is now tvtag -- an entertainment-based social network for TV shows, live sports games and movies. Whenever you tune in to watch your favorite show, you can use tvtag to check-in to that specific episode, follow a live feed with the rest of the community, get involved in the conversation and even earn fun digital stickers. And you can do all of this either on the web or through tvtag's great mobile apps.

15. Pheed

Pheed is a newcomer to the social networking world, but kids who crave the latest, coolest, newest apps to use have been quick to jump on this one. It brings together the best of a lot of other popular social sites like Facebook, Twitter, Tumblr and Instagram -- all rolled into one super hip, super young social network on the web and mobile. Could it be the next big thing? We'll just have to wait and see.